Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA.
Hum Mol Genet. 2013 Dec 1;22(23):4726-38. doi: 10.1093/hmg/ddt326. Epub 2013 Jul 10.
The small airway epithelium (SAE), the first site of smoking-induced lung pathology, exhibits genome-wide changes in gene expression in response to cigarette smoking. Based on the increasing evidence that the epigenome can respond to external stimuli in a rapid manner, we assessed the SAE of smokers for genome-wide DNA methylation changes compared with nonsmokers, and whether changes in SAE DNA methylation were linked to the transcriptional output of these cells. Using genome-wide methylation analysis of SAE DNA of nonsmokers and smokers, the data identified 204 unique genes differentially methylated in SAE DNA of smokers compared with nonsmokers, with 67% of the regions with differential methylation occurring within 2 kb of the transcriptional start site. Among the genes with differential methylation were those related to metabolism, transcription, signal transduction and transport. For the differentially methylated genes, 35 exhibited a correlation with gene expression, 54% with an inverse correlation of DNA methylation with gene expression and 46% a direct correlation. These observations provide evidence that cigarette smoking alters the DNA methylation patterning of the SAE and that, for some genes, these changes are associated with the smoking-related changes in gene expression.
小气道上皮(SAE)是吸烟引起肺部病变的第一部位,其基因表达会发生全基因组范围的变化以响应吸烟。鉴于越来越多的证据表明表观基因组可以快速响应外部刺激,我们评估了吸烟者和非吸烟者的 SAE 中的全基因组 DNA 甲基化变化,以及 SAE DNA 甲基化的变化是否与这些细胞的转录输出有关。通过对非吸烟者和吸烟者的 SAE DNA 进行全基因组甲基化分析,数据确定了 204 个在吸烟者的 SAE DNA 中与非吸烟者相比差异甲基化的独特基因,其中 67%的差异甲基化区域发生在转录起始位点的 2 kb 内。在差异甲基化的基因中,有与代谢、转录、信号转导和运输相关的基因。对于差异甲基化的基因,有 35 个基因的表达与 DNA 甲基化相关,其中 54%的基因的 DNA 甲基化与基因表达呈负相关,46%的基因呈正相关。这些观察结果提供了证据表明,吸烟改变了 SAE 的 DNA 甲基化模式,并且对于一些基因,这些变化与吸烟引起的基因表达变化有关。